From ae03da75d16d5d6e00c6f12102846509060a1138 Mon Sep 17 00:00:00 2001
From: Simon Marlow <marlowsd@gmail.com>
Date: Mon, 28 Jun 2010 09:05:36 +0000
Subject: [PATCH] during shutdown, only free the heap if we waited for foreign
 calls to exit

---
 rts/RtsStartup.c |    7 +++++--
 rts/sm/Storage.c |    4 ++--
 rts/sm/Storage.h |    2 +-
 3 files changed, 8 insertions(+), 5 deletions(-)

diff --git a/rts/RtsStartup.c b/rts/RtsStartup.c
index b0cddbd..d7a8d95 100644
--- a/rts/RtsStartup.c
+++ b/rts/RtsStartup.c
@@ -450,8 +450,11 @@ hs_exit_(rtsBool wait_foreign)
     /* free hash table storage */
     exitHashTable();
 
-    // Finally, free all our storage
-    freeStorage();
+    // Finally, free all our storage.  However, we only free the heap
+    // memory if we have waited for foreign calls to complete;
+    // otherwise a foreign call in progress may still be referencing
+    // heap memory (e.g. by being passed a ByteArray#).
+    freeStorage(wait_foreign);
 
 #if defined(DEBUG)
     /* and shut down the allocator debugging */
diff --git a/rts/sm/Storage.c b/rts/sm/Storage.c
index c9422e6..10a0a38 100644
--- a/rts/sm/Storage.c
+++ b/rts/sm/Storage.c
@@ -213,10 +213,10 @@ exitStorage (void)
 }
 
 void
-freeStorage (void)
+freeStorage (rtsBool free_heap)
 {
     stgFree(generations);
-    freeAllMBlocks();
+    if (free_heap) freeAllMBlocks();
 #if defined(THREADED_RTS)
     closeMutex(&sm_mutex);
 #endif
diff --git a/rts/sm/Storage.h b/rts/sm/Storage.h
index f6c50ad..e541193 100644
--- a/rts/sm/Storage.h
+++ b/rts/sm/Storage.h
@@ -19,7 +19,7 @@
 
 void initStorage(void);
 void exitStorage(void);
-void freeStorage(void);
+void freeStorage(rtsBool free_heap);
 
 /* -----------------------------------------------------------------------------
    Storage manager state
-- 
1.7.10.4